Abstract: At 8:45 a.m. on July 26, 2019, Employee #1, an electrician, was engaged in electrical work at a retail facility. He was working on a GE A-Series II Panelboard, rated 600 amperes and 480 volts, and was in the process of connecting wires to a 20-ampere circuit breaker for a rooftop unit. The panel was energized and the dead front was removed. The bottom of the panel was located approximately 26 inches above the floor. Due to the lack of the dead front cover, there was an opening approximately 18.5 inches wide and 62.5 inches tall, exposing energized components. The electrician was arranging wires near the top interior of the panel in order to make the connection at the breaker located on the left side of the panel. An arc flash/explosion occurred, pushing him back several feet to the wall behind him and igniting his hair. The electrician ran out of the room, and a coworker helped to put out the fire on top of his head. The electrician was transported to the hospital and admitted for treatment of second and third degree burns to his left arm and the top of his head, and less severe burns to his forehead, cheek, and nose.